Method and apparatus for producing a porosity log of a subsurface formation corrected for detector standoff
CA 2074594 C · Owner: Stromswold, David Charles · Inventors: Lyle, W. D. Jr.; Leland, Frank Paynter; Allen, Linus Scott
Overview
Its claims, description and drawings are in the Canadian Patents Database.
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A borehole logging tool is lowered into a borehole traversing a subsurface formation and a neutron detector measures the die-away of nuclear radiation in the formation. A model of the die-away of nuclear radiation is produced using exponential terms varying as the sum of borehole, formation and thermal neutron background components. Exponentially weighted moments of both the die-away measurements and die-away model are determined and equated. The equated moments are solved for the ratio of the borehole to formation amplitude components of the measurements. The formation decay constant is determined from at least the formation and thermal neutron background terms of the weighted measurement …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed July 24, 1992 and granted May 20, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 24, 2014.
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